The present invention relates in general to latching mechanisms which are designed to securely connect or attach one object to another object, such as a boat to a boat trailer. More specifically the present invention relates to an automatic latching mechanism which is attached to a boat trailer and which securely receives the U-bolt which is fixed to the bow of a boat.
Boat trailers for transporting, launching, and retrieving fishing boats and pleasure boats are widely used by the boating public. While a variety of different winch and tow rope arrangements have been and may be employed, one commonly used element of such arrangements is an U-bolt or eyelet of some configuration which is fixed to the bow of the boat, typically on the centerline of the boat. Since the bow U-bolt is typically located in a similar position, independent of the particular boat style, it provides one aspect of some consistency between varying designs, styles, sizes, and makes of boats.
A review of earlier patents indicates that one disadvantage, as viewed by other designers, with a winch and tow rope arrangement is that at least two people are required to effectively retrieve and load the boat onto the trailer. One person is normally needed to connect the tow line to the boat and operate the winch. The other person is required to navigate and maintain the boat in alignment with the boat trailer. Since there are situations where two people are not always available to load a boat onto a boat trailer, it has been suggested that it would be an improvement to existing trailer designs with a winch and tow rope arrangement if an automatic latching mechanism could be provided which securely attaches to the U-bolt of the boat bow. While an automatic latching mechanism on the boat trailer would conceivably only require one individual to load the boat onto the boat trailer, as a practical matter you would prefer to have one individual handling the boat and a second individual handling the boat trailer and the vehicle towing the boat trailer. This is the most efficient approach. However, even with two individuals and even if a winch and tow rope arrangement is available, there is still a certain awkwardness to the currently practiced method. While one individual will stay with the trailer and tow vehicle, the individual directing the boat onto the trailer may be required to lean forward over the bow and hook the winch rope into the U-bolt. It would thus be an improvement to this procedure if an automatic latching mechanism could be provided.
Over the years certain designers have tried to provide improvements to the winch and tow rope arrangements, even suggesting elimination of those arrangements. One such earlier design effort involves the use of a latching mechanism with a locking pin. This type of design is represented by U.S. Pat. No. 3,989,267 which issued Nov. 2, 1976 to Robinson. In order to perform its intended function, the pin 27 of U.S. Pat. No. 3,989,267 must be initially pulled out, set in a cocked position, and biased by spring 33 against the edge of trigger plate 30. The associated spring compression and preload is a disadvantage in that this arrangement results in greater wear and a greater risk that the cocked arrangement will be jarred loose and released prior to connecting to the U-bolt. If the cocked arrangement is jarred loose and released, it would not be properly conditioned to receive and thereafter securely hold the U-bolt. Another concern with this design is the constant load on pin 27 when it is inserted through the U-bolt due to the weight of the boat.
While the '267 patent represents one trailer latch mechanism which does not involve a winch and tow rope arrangement, other similar design arrangements are represented by the following patents:
______________________________________ PATENT NO. PATENTEE ISSUE DATE ______________________________________ 3,938,829 Anderson Feb. 17, 1976 4,114,920 Boettcher Sep. 19, 1978 4,919,446 Higgins Apr. 24, 1990 ______________________________________
In evaluating the efficiency, reliability, cost and suitability of these other designs, it is important to keep in mind that reliability is of primary importance. The preferred latching mechanism is one which is normally unloaded and not in a highly spring-biased condition, one which operates in an automatic manner and is virtually fool-proof, one which is suitable for a wide range of boat shapes and sizes, and one which will securely anchor the boat to the trailer regardless of external conditions such as the angle of the trailer, size and weight of the boat, and the speed at which the boat ramps up onto the boat trailer. It is also preferred that the latching mechanism be designed such that it is extremely strong and any wear loading is minimal. The present invention provides each of these desirable features with a structure that is novel and unobvious.